Method of repairing high pressure slush pumps



25, 1964 v. R. MATTINGLY 3,145,461

METHOD OR REPAIRING HIGH PRESSURE SLUSH PUMPS Filed May 28, 1963 3 Sheets-Sheet 1 I NVENTOR.

Aug. 25, 1964 Filed May 28, 1963 METHOD OF REPAIRING HIGH PRESSURE SLUSH PUMPS v. R. MATTINGLY 3,145,461

o o \J 26 00000 m 230 23a 95 H a BY IM W W 3 Sheets-Sheet 2 v 1954 v. R. MATTINGLY 3,145,461

METHOD OF REPAIRING HIGH PRESSURE SLUSH PUMPS Filed May 28, 1963 5 Sheets-Sheet 5 INVENTOR.

BY wl w United States Patent 3,145,461 METHOD OF REPAIRING HIGH PRESSURE SLUSH PUMPS Virdean R. Mattingly, 6502. Country Club, Houston, Tex. Filed May 28, I63, Ser. No. 233,838 Claims. (Cl. 29-402) This invention relates to a method of repairing high pressure slush pumps and refers more particularly to the repair of high pressure slush pumps used in oil fields and the like where cracks have developed in the necks providing the flow passage connections between the pump barrels and the valve pots.

In the specification and claims the terms high pressure pumps, pump body and pumps actually refer to the fluid end of the pumps as distinguished from the power end.

Pumps of the type to which this invention pertains are well known to industry and are widely used for circulating fluids such as, for example, drilling mud in the drilling of oil and gas wells. The pumps comprise the pump barrel which houses a removable liner and has at each end a pump chamber which communicates with the valve pots. Some such pumps have but a single barrel, but most of the pumps have two such barrels. For each chamber for each barrel there is a valve pot for a suction valve and a valve pot for a discharge valve. The valve pots are connected through necks to the barrel and these necks have proven to be the place where failure is most likely to occur. The necks constitute the fluid passages between the pump barrels and the valve pots and the Wall thickness of these necks usually is less than the Wall thickness of the valve pots and the barrels. Attempts have been made to remove a section of the pump surrounding a crack that has developed and fill this in with weld material. However, for the most part, such efforts have not been entirely satisfactory and this is particularly true in the caseof large breaks. a

An object of this invention is to provide a method of repairing pumps in which the relatively weak neck sections are actually replaced by heavier sections so that the pump when repaired, no longer has what has proven to be the troublesome, relatively thin-walled neck sections.

Another object is to provide a method of repairing such pumps in which the repaired pump is usually stronger than the original pump was, in the critical sections where breaks or cracks usually occur.

Another object is to provide a method of repairing such pumps in which one of the valve pots and at least a part of the barrel is removed with the cracked neck section and the replacement part having a thick-walled section which replaces the cracked neck as well as providing the replacement component is secured in place so that the relatively weak neck is actuahy removed in the rebuilt pump.

Another object is to provide a method of repairing such pumps in which the defective portion or" the pump is completely cut from the pump, a relatively narrow land is provided on the mother metal adjacent the cut, the land being utilized to align a replacement part by engaging a machined surface formed thereon, the lands and machined surfaces maintaining alignment of the new part according to the arrangement of the original pump, during the welding operation.

Another object is to provide a method of repairing such pumps in which the bridges between pump parts, which bridges are not welded but which span welds during the repair, are heated to a substantially higher temperature than the normal Welding temperature to which the main body of the pump is subjected during the welding operation so as to minimize stresses that develop during cooling of the rebuilt pump.

Another object is to provide a novel method of heating the pump during the repair work.

Other and further objects of the invention will appear from the following description of the method of this invention taken in conjunction with the drawings which illustrate the repair of such pumps. In the drawings:

FIGS. 1, 2, 3 and 9 illustrate a pump which is being repaired by having two of the suction valve pots for one of the pump barrels replaced in order to repair cracks that have developed in the necks between these pump valves and the respective barrels.

FIG. 1 is a top plan view of the pump;

FIG. 2 is a view taken along the line 2-2 in FIG. 1 in the direction of the arrows;

FIG. 3 is a view on an enlarged scale, taken along the line 33 in FIG. 1;

FIG. 9 is a view on an enlarged scale of the section indicated in FIG. 2;

FIGS. 4, 5 and 10 illustrate another pump in which both barrels are being replaced in order to repair cracks that have developed in the pumps in the necks between the valve pots and the barrels;

FIG. 4 is an end view of the pump partially in section and showing one barrel removed, taken from the cylinder head end;

FIG. 5 is a view taken along the line 5-5 in FIG. 4; FIG. 10 is an enlargement of the section shown in FIG.

FIG. 6 illustrates a modification of FIGS. 4 and 5 wherein only a part of a barrel is being removed and shows the replacement part welded in place; and

FIGS. 7 and 8 illustrate a different type of pump known generally as the exposed liner pump and illustrate replacement of the barrels of such pumps.

In general, the method of this invention involves the cutting of a defective neck and one of the component parts connected thereto from the pump in such a way as to remove all of the damaged neck. A replacement part having a thicker section to fill the gap theretofore occupied by the neck is utilized. The replacement part has an opening to replace the flow passage of the removed neck and is provided with a machined surface surrounding the opening. Relatively narrow lands are formed on the mother metal adjacent the out which will engage with the machined surface of the replacement part to align and position the replacement part in the same position occupied by the part that was removed. Sufiicient mother metal is removed, if necessary, adjacent the lands, to provide a welding space between the mother metal and the machined surface of the replacement part. This space is then filled with welding material, and the welding on both sides of the narrow land causes it to fuse to the machined surface on the replacement part.

During the welding operation, the entire pump or main body thereof is preferably heated in accordance with normal welding practice; but bridging par-ts, such as manifolds, which themselves are not welded but which span welded parts, are heated to a higher temperature, usually in the order of F. to 200 F. higher than the remainder of the pump body prior to the welding and as it proceeds. Of course, during the actual welding, the parts closely adjacent the weld are highly heated. It has been found by this method of heating the bridges, creation of stresses is minimized upon cooling of the entire pump body. Upon completion of the replacement of the component parts, it is preferable to stress relieve the pump through usual heat treating practices. I

Referring in detail to the drawings for a description of certain illustrative embodiments of the present method, FIGS. 1, 2, 3 and 9 illustrate a pump in which the two left end pots are to be removed in order to repair cracks that appeared in the pots and necks of the pump. The

pump barrels are illustrated at and 11. The discharge valve pots 12, 13, 14 and 15 are arranged as shown at the ends of the pump barrels. The suction pots of the original pump end are shown at 16 and 17 and at 18 a replacement of one of the suction pots is shown partially welded in position. At 19 there is shown the pump end with one of the suction pots removed and with the scar prepared for receiving a replacement part. By reference to FIG. 1, and particularly the scar 19, it is seen that in removing the neck, the actual connection of the neck with the pump barrel is also removed. By reference to the replacement part 18, it is seen that the increased diameter or wall thickness of the replacement valve pot (compared to 16 and 1'7) is such that the cracked neck will be completely replaced when the new pump part is secured in place. The extra thickness of the new component or replacement part provides in effect the connecting neck. Thus, the relatively thin-walled neck which originally gave the trouble has been completely removed and replaced by a much stronger element.

The scar on the mother metal is provided with lands for positioning the replacement part in proper position so its axis and outlets will conform to the position of those of the original pot. The manner in which this is done is best shown in FIG. 3. Referring to FIG. 3, 19a illustrates the opening through the scar 19 and the land parts formed on the scar are shown at 20, 29a and 20b. The distance between the inner edge of the parts 2%, 20a and 20b and the opening 19a are somewhat exaggerated in this drawing for the purposes of illustration. In actual practice, this distance will vary from approximately /8 inch to approximately /2 inch, and the metal between the edges of the lands and the opening will be tapered to provide a welding space between it and the replacement part. A cutting torch may be used for this purpose. Similarly, the scar between the outer edges of the land parts and the outer edge of the scar will be tapered so as to provide a welding space to receive welding material. In the drawing, the land parts are shown as discontinuous. They may be continuous or discontinuous, but in any event should be sufficient to properly orient the re placement part when placed thereagainst. These lands in actual practice are formed in the preferred performance of the method by a milling machine. When sufiicient mother metal exists after removal of the cracked neck, then the lands are formed on the mother metal and excess thickness of the metal is removed by a welding torch as indicated by the scar marks 1%. When sufficient mother metal does not remain for this purpose, the surface of the scar may be built up sufliciently for the land to be formed thereon. For example, a rod may be welded on the scar and a land formed on the outer surface of the rod.

The replacement valve pot, such as 18, has its outer surface machined at least adjacent the part to confront the scar. In practice, it is usually preferred to turn the entire surface in a lathe in the interest of simplicity, and to utilize for this reason a cylindrically shaped valve pot. The valve pot is provided with a suitable opening for making connection with the opening 19a and the surface around this opening of course must be machined in one way or another to provide the reference surface for engagement with lands 20, 20a and 20b.

FIG. 1 illustrates valve pct 18 landed in position to receive the weld material. The welding space between the machined surface of valve pot 18 and the scar is shown partially filled with welding material and this space will be completely filled in completing the welding operation. Welding material is also introduced interiorly of the valve pot to weld between the opening 19a and the inner edges of the lands 20, 20a and 20b. This is illustrated best in FIG. 9 on an exaggerated scale. By welding on each side of the land and by utilizing narrow lands, the land is actually fused to the machined surface on the replacement part so that the weld is complete.

In cutting the valve pots from the fluid end of the pump, the valve pot must be cut from the manifold as well. This cut is upon the line'll shown in FIG. 2. The lower end of the valve pot is machined to provide a reference surface and a land is machined on the upper end of the manifold in the same fashion as explained above with reference to lands 29, 26a and 20b on the scar 19. This land engages the under end of the valve pot to provide this reference. When in position the joint is completed by suitable welding as illustrated.

The embodiment of this invention relating to the replacement of complete barrels will be explained in connection with FIGS. 4 and 5. barrel is shown to have been cut from the fluid end of the pump. The right hand replacement pump barrel 22 is shown maintained in place ready for welding.

The manner in which the lands are formed for positioning the replacement barrel 22 is best disclosed by reference to the space where the left hand barrel has been removed. On cutting the barrel and the necks out, a scar as illustrated generally at 23 will be provided on the under end of the discharge valve pot. A similar scar 24 will remain on the suction valve pot; These are machined, preferably in a mill, to provide lands 23a and 24a shown in dotted lines, respectively, which may or may not extend completely around the openings in the valve pot connections. In any event, they will be of sufficient extent circumferentially about the opening to serve to position the replacement barrel. Once the lands 23a and 24a have been formed, the material will be out therefrom to provide only narrow lands to the contour shown in dotted lines in FIG. 4. By reference to the right hand barrel in Fl 4, it will be seen that these dotted lines correspond generally to the lands that were prepared for receiving the right hand barrel. The enlargement of FIG. 10 illustrates this better on an exaggerated basis in connection with land 24:: when the welding space on each side of the land 24a is apparent.

In rebuilding the pump in this fashion, it is usually preferable to remove both barrels and to provide the lands for both barrels as indicated before either barrel is placed in position.

The barrels themselves are preferably cylindrical in shape and have their outer surfaces machined to a predetermined contour at least adjacent the openings such as 22:: and 22b for communication with the valve pots. Care must be taken in the formation of the lands and the machined surfaces of the barrels surrounding the openings 22a and 22b so that with these surfaces in engagement the center line of the barrel will be aligned with the center line of the barrel that originally existed in the pump. This is necessary in order that the liners in the pumps will be in alignment with the power ends of the pumps (the power ends are not shown). This may be accomplished by marking a reference point on the pump body before the original bands are removed, and establishing the respective positions of the center lines relative to this point and each other. These measurements are then correlated to the lands 23a and 24a and to the respective machined surfaces of the replacement bands.

Once the various surfaces and lands have been prepared, then the pump barrels may be assembled in the openings and the welding commenced. As a preparation for welding the entire pump and body should be heated in accordance with normal Welding practice before welding commences (this may be in the neighborhood of 250 F. and preferably between 225 F. and 275 F.) and spanning bridges such as the manifold 25 and manifold 26, though themselves not welded, should be heated between F. and 200 F. hotter than the main body of the fluid end. If the main body of the pump is heated to 250 F. it has been found that 400 F. is a satisfactory temperature for the bridges. peratures are maintained during the Welding operation.

FIG. 5 illustrates completion of the weld iu the left hand In FIG. 4 the left hand The respective temend of the pump barrel whereas the right hand end has not in anywise been welded, but is ready for welding. This has been done for illustrative purposes, but usually it is preferred to conduct all of the welds on a sort of progressive basis so they are built up more or less together according to good welding practices.

Once the welding operation has been completed, preferably the entire fluid end of the pump is stress relieved in accordance with usual practice.

In FIG. 6, a modification of the method is shown wherein only a part of one end of the pump barrel has been replaced. The only difference between the modification of FIG. 6 and that of FIGS. 4 and 5 is that only a part of the original pump barrel for the left hand barrel as shown in FIG. 4 has been removed. Therefore, 27 represents the remaining portion of the original pump barrel and 28 represents the replacement end for the barrel. The relative thickness of the original and replacement barrels is illustrated, and it is this thicker portion of the replacement barrel that removes the neck portion or in efiect provides the connection between the barrel and valve pot. The connection of the pot 23b to the replacement barrel portion 28 is the same as that described heretofore in conjunction with FIGS. 4 and 5. However, a land 27a is formed on the end of the mother metal of the original pump part 27 and the right hand end of replacement element 28 is machined to provide a reference surface for engagement with the land 27a. The welding is completed as heretofore described in conjunction with the foregoing figures. The parts 25 and 26 are preferably pre-heated hotter than the remainder of the main body of the pump.

FIGS. 7 and 8 illustrate the repair, in accordance with the method of this invention, of a different type of pump commonly known as an exposed liner pump. This pump, instead of having two barrels each of which extend completely through the pump, has four pump barrel ends. In FIG. 8, barrel ends 30 and 31 are shown. These are connected by means of spacer bars 32 and 33.

In the drawings, is an illustration of the removal and replacement of the left hand or cylinder head ends of the pump barrels. In FIG. 7, 34 and 35 represent the scar on the discharge and suction valve pots, respectively, after the left hand forward pump barrel ends have been removed. A replacement pump barrel 30 is shown installed in the right end of the forward end of the pump (FIG. 7). The pump barrel end 39 is shown seated against land 36a formed on the lower end of the discharge valve pot 36. The suction valve pot 37 is provided with a land 37a against which barrel end 30 is seated. The scars 34 and 35 will be provided with similar lands to receive a pump end barrel and this will preferably be done prior to the welding of pump end 30 into place. The particular sequence shown in the drawing has been pictured for illustrative purposes.

FIG. 8 illustrates the manner in which the replacement element 30 is secured to the braces 32 and 33. These braces are formed with narrow lands to serve as references for engagement with the machined inner end of element 30. The machined end provides a reference with the element 30 engaging the lands on the braces 32 and 33 and also the lands on the valve pots 36 and 37. The openings in the element are aligned with the valve pot and the center line of the element is on the same center line as the original removed barrel end.

In this modification of the invention the bridging manifolds 38 and 39 are heated approximately 100 F. to 200 F. hotter than the main body of the pump during the welding operation, as in the preceding embodiments.

Experience has shown that in carrying out the method of this invention, it is preferable to heat the main body of the pump in the order of 250 F. This of course is subject to considerable leeway on either side, and best results have been found to occur when the bridging portions are heated to the order of 400 F. This of course 6 is subject to some leeway; and if the main body of the pump is not heated as high, then a somewhat lower value for the extra heating is indicated and vice versa.

It will be seen that the ends and objects of this invention have been attained. The method provides a means of salvaging pumps which have been damaged beyond repair in accordance with usual methods. Due to the many thousands of dollars represented by these pumps, their repair by this method represents considerable economic savings. The method provides a repaired pump which is actually stronger than the original pump in that the relatively thin necks in which most of the cracks have occurred in the past, have been replaced by the relatively very strong thickened elements of the replacement element. The method is versatile in that a damaged pump may be reviewed and repaired in a number of manners in order to effect the most economical repair or rebuilding of the pump. In some instances, one or more valve pots are indicated for replacement in the interest of economy. In other instances, one or more pump barrels or one or more parts of a pump barrel are indicated as the most economical procedure. Pumps rebuilt in accordance with the conception of this invention have proven entirely satisfactory in the rigorous usage to which they are ordinarily subjected in the oil fields.

From the foregoing it will be seen that this invention is one well adapted to attain all of the ends and objects hereinabove set forth, together with other advantages which are obvious and which are inherent to the method.

It will be understood that certain features and subcombinations are of utility and may be employed without reference to other features and subcombinations. This is contemplated by and is within the scope of the claims.

As many possible embodiments may be made of the invention without departing from the scope thereof, it is to be understood that all matter herein set forth or shown in the accompanying drawings is to be interpreted as illustrative and not in a limiting sense.

The invention having been described, what is claimed 1s:

1. The method of repairing a high-pressure, heavyduty, piston-type oil field slush pump that has a crack in the neck extending between a pump barrel and one of its valve pots comprising the steps of cutting the defective neck and one of at least the adjacent part of the pump barrel and the adjacent valve pot from the remainder of the pump; machining a surface on a heavy walled replacement element for the cutaway of the pump barrel part and the valve pot, the thickness of the replacement element at and adjacent tothe machined surface being such as to replace the damaged and removed neck part; machining narrow land parts on the remaining one of the pump barrel part and the valve pot to provide a land for the machined surface of the replacement element placing the center line of the replacement element in the same position relative to the center line of the remaining one of the pump barrel part and the valve pot that the center lines of the originals bore to each other with the machined surface landed thereagainst; placing the replacement element in said landed position; and welding said replacement element, while maintaining it in said landed position, to the remaining onefilling the spaces between the machined surface and the body of the remaining one adjacent the narrow land parts with weld material to completely enclose the connection therebetween and to fuse the narrow land parts to the rnachined surface of the replacement part.

2. The method of claim 1 where the end of the pump barrel adjacent the damaged neck is removed and the inner end of the replacement element is machined; forming narrow land parts on the portion of the pump barrel from which the removed part was severed to provide an axial length of the repaired pump barrel equal to that of the original pump barrel when the machined surface 7 of the removed part is landed thereagainst; and welding the adjacent machined surface and narrow land, filling the space therebetween with weld material, and fusing the land parts to the machined surface.

3. The method of claim 1 wherein the manifolds connecting valve pots which bridge a replacement element being welded in place are heated substantially higher than the main body of the pump during the welding operation.

4. The method of claim 3 wherein the main body of the pump is heated to between 225 F. and 275 F. during the welding operation.

5. The method of repairing a high-pressure, heavyduty, piston-type oil field slush pump that has a crack in the neck extending between a pump barrel and one of its valve pots comprising the steps of cutting the defective neck and at least the adjacent end of the pump barrel from the pump, the connections between the barrel and the valve pots, that are cut, being cut generally arcuately; machining arcuate surfaces on a barrel replacement adjacent openings therein to cornmunciate with the valve pots the distance between the center line of the barrel replacement and the machined surfaces being great enough to provide a replacement for the removed necks when the new part is in place; forming narrow lands on the arcuate severed portions of the valve pots measured so that with the replacement in place with the machined surfaces engaging the narrow lands on the valve pots the center line of the replacement has the same relation to the center line of the valve pots that the center line of the original had; placing the replacement in position with the machined surfaces in landed position; and maintaining said position while filling the spaces between the machined surfaces and the valve pots with weld material and fusing the lands to the machined surfaces.

6. The method of repairing a high-pressure, heavyduty, piston-type oil field slush pump that has a crack in the neck extending between a pump barrel and at least one valve pot at each end of the barrel comprising the steps of cutting the barrel from the pump and removing the necks between it and the valve pots connected with it; machining arcuate surfaces on a replacement, adjacent openings therein to communicate with the valve pots the distance between the center line of the replacement and the machined surfaces being great enough to provide a replacement for the removed necks when the new part is in place; forming narrow lands on the arcuate severed portions of the valve pots measured so that with the replacement in place with the machined surfaces engaging the narrow lands on the valve pots the center line of the replacement has the same relation to the center line of the valve pots that the center line of the original had; placing the replacement in position with the machined surfaces in landed positions; and maintaining said position while the spaces between the machined surfaces and the valve pots are filled with weld material and the lands are fused to the machined surfaces.

7. The method of claim 6 wherein the pump has two barrels and both barrels are removed and replaced in the same manner and the manifolds connecting the suction valve pots and the exhaust valve pots of each barrel are heated to a substantially higher temperature than the main body of the pump during the welding operation.

8. The method of repairing a high-pressure, heavy-duty, piston-type oil field slush pump that has a crack in the neck extending between a pump barrel and one of its valve pots comprising the steps of cutting the defective neck from the pump barrel and cutting the connection of the valve pot to its manifold so as to remove the valve pot and defective neck; machining surfaces on a replacement valve pot, one surrounding an opening for connection to the pump barrel opening and the other surrounding an opening for connection to the manifold opening; the first-identified machined surface forming a part of a cylinder coaxial with the interior of the pot and spaced from the axis thereof a sufficient distance to replace all of the removed neck that extended between the barrel and the original valve pot; forming narrow machinedlands about the barrel opening and the manifold opening for engagement with the respective machined surfaces on the valve pot replacement positioned to engage the machined surfaces to orient the replacement pot in like manner to the original; and maintaining said replacement valve pot in oriented position while welding the same in place, filling the spaces between the machined surfaces and adjacent pump barrel and manifold with weld material and fusing the lands to the machined surfaces.

9. The method of claim 1 wherein bridging parts of the pump are heated to a substantially higher temperature in the order from F. to 200 F. hotter than the main body of the pump which is heated in accordance with good welding practice during the welding operation.

10. In the method of repairing high-pressure, heavyduty slush pumps wherein one or more cracked necks are replaced between a pump barrel and valve pots accompanied by replacement of one element selected from the barrel and the valve pots, the improvement which results in the combination therewith of the steps of heating the main body of the slush pump in accordance with good welding practice and heating bridging parts which have no weld thereon but which span welded parts to a substantially higher temperature than the temperature of the main body of the pump during the welding process.

References Cited in the file of this patent UNITED STATES PATENTS 2,632,944 Kittelson Mar. 31, 1953 2,944,336 Stanclifi et al July 12, 1960 3,039,182 Harman June 19, 1962 

1. THE METHOD OF REPAIRING A HIGH-PRESSURE, HEAVYDUTY, PISTON-TYPE OIL FIELD SLUSH PUMP THAT HAS A CRACK IN THE NECK EXTENDING BETWEEN A PUMP BARREL AND ONE OF ITS VALVE POTS COMPRISING THE STEPTS OF CUTTING THE DEFECTIVE NECK AND ONE OF AT LEAST THE ADJACENT PART OF THE PUMP BARREL AND THE ADJACENT VALVE POT FROM THE REMAINDER OF THE PUMP; MACHINING A SURFACE ON A HEAVY WALLED REPLACEMENT ELEMENT FOR THE CUTAWAY OF THE PUMP BARREL PART AND THE VALVE POT, THE THICKNESS OF THE REPLACEMENT ELEMENT AT AND ADJACENT TO THE MACHINED SURFACE BEING SUCH AS TO REPLACE THE DAMAGED AND REMOVED NECK PART; MACHINING NARROW LAND PARTS ON THE REMAINING ONE OF THE PUMP BARREL PART AND THE VALVE POT TO PROVIDE A LAND FOR THE MACHINED SURFACE OF THE REPLACEMENT ELEMENT PLACING THE CENTER LINE OF THE REPLACEMENT ELEMENT IN THE SAME POSITION RELATIVE TO THE CENTER LINE OF THE REMAINING ONE OF THE PUMP BARREL PART AND THE VALVE POT THAT THE CENTER LINES OF THE ORIGINALS BORE TO EACH OTHER WITH THE MACHINED SURFACE LANDED THEREAGAINST; PLACING THE REPLACEMENT ELEMENT IN SAID LANDED POSITION; AND WELDING SAID REPLACEMENT ELEMENT, WHILE MAINTAINING IT IN SAID LANDED POSITION, TO THE REMAINING ONE FILLING THE SPACES BETWEEN THE MACHINED SURFACE AND THE BODY OF THE REMAINING ONE ADJACENT THE NARROW LAND PARTS WITH WELD MATERIAL O COMPLETELY ENCLOSE THE CONNECTION THEREBETWEEN AND TO FUSE THE NARROW LAND PARTS TO THE MACHINED SURFACE OF THE REPLACEMENT PART. 